Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
[linux-2.6.git] / drivers / acpi / ec.c
index f0e8216..b19a18d 100644 (file)
@@ -1,7 +1,7 @@
 /*
- *  ec.c - ACPI Embedded Controller Driver (v2.0)
+ *  ec.c - ACPI Embedded Controller Driver (v2.1)
  *
- *  Copyright (C) 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
+ *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
  *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
@@ -26,7 +26,7 @@
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
 
-/* Uncomment next line to get verbose print outs*/
+/* Uncomment next line to get verbose printout */
 /* #define DEBUG */
 
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/delay.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
 #include <linux/interrupt.h>
 #include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
 #include <asm/io.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
-#include <acpi/actypes.h>
+#include <linux/dmi.h>
+
+#include "internal.h"
 
 #define ACPI_EC_CLASS                  "embedded_controller"
 #define ACPI_EC_DEVICE_NAME            "Embedded Controller"
@@ -65,24 +67,26 @@ enum ec_command {
        ACPI_EC_COMMAND_QUERY = 0x84,
 };
 
-/* EC events */
-enum ec_event {
-       ACPI_EC_EVENT_OBF_1 = 1,        /* Output buffer full */
-       ACPI_EC_EVENT_IBF_0,            /* Input buffer empty */
-};
-
 #define ACPI_EC_DELAY          500     /* Wait 500ms max. during EC ops */
 #define ACPI_EC_UDELAY_GLK     1000    /* Wait 1ms max. to get global lock */
-#define ACPI_EC_UDELAY         100     /* Wait 100us before polling EC again */
+#define ACPI_EC_MSI_UDELAY     550     /* Wait 550us for MSI EC */
+
+#define ACPI_EC_STORM_THRESHOLD 8      /* number of false interrupts
+                                          per one transaction */
 
 enum {
-       EC_FLAGS_WAIT_GPE = 0,          /* Don't check status until GPE arrives */
        EC_FLAGS_QUERY_PENDING,         /* Query is pending */
-       EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent for status change */
-       EC_FLAGS_NO_GPE,                /* Don't use GPE mode */
-       EC_FLAGS_RESCHEDULE_POLL        /* Re-schedule poll */
+       EC_FLAGS_GPE_STORM,             /* GPE storm detected */
+       EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
+                                        * OpReg are installed */
+       EC_FLAGS_BLOCKED,               /* Transactions are blocked */
 };
 
+/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
+static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
+module_param(ec_delay, uint, 0644);
+MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
+
 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
 /* External interfaces use first EC only, so remember */
 typedef int (*acpi_ec_query_func) (void *data);
@@ -95,20 +99,24 @@ struct acpi_ec_query_handler {
        u8 query_bit;
 };
 
-static struct acpi_ec {
-       acpi_handle handle;
-       unsigned long gpe;
-       unsigned long command_addr;
-       unsigned long data_addr;
-       unsigned long global_lock;
-       unsigned long flags;
-       struct mutex lock;
-       wait_queue_head_t wait;
-       struct list_head list;
-       struct delayed_work work;
-       atomic_t irq_count;
-       u8 handlers_installed;
-} *boot_ec, *first_ec;
+struct transaction {
+       const u8 *wdata;
+       u8 *rdata;
+       unsigned short irq_count;
+       u8 command;
+       u8 wi;
+       u8 ri;
+       u8 wlen;
+       u8 rlen;
+       bool done;
+};
+
+struct acpi_ec *boot_ec, *first_ec;
+EXPORT_SYMBOL(first_ec);
+
+static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
+static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
+static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 
 /* --------------------------------------------------------------------------
                              Transaction Management
@@ -125,7 +133,7 @@ static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 {
        u8 x = inb(ec->data_addr);
        pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
-       return inb(ec->data_addr);
+       return x;
 }
 
 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
@@ -140,181 +148,220 @@ static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
        outb(data, ec->data_addr);
 }
 
-static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
+static int ec_transaction_done(struct acpi_ec *ec)
 {
-       if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
-               return 0;
-       if (event == ACPI_EC_EVENT_OBF_1) {
-               if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
-                       return 1;
-       } else if (event == ACPI_EC_EVENT_IBF_0) {
-               if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
-                       return 1;
-       }
-
-       return 0;
+       unsigned long flags;
+       int ret = 0;
+       spin_lock_irqsave(&ec->curr_lock, flags);
+       if (!ec->curr || ec->curr->done)
+               ret = 1;
+       spin_unlock_irqrestore(&ec->curr_lock, flags);
+       return ret;
 }
 
-static void ec_schedule_ec_poll(struct acpi_ec *ec)
+static void start_transaction(struct acpi_ec *ec)
 {
-       if (test_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags))
-               schedule_delayed_work(&ec->work,
-                                     msecs_to_jiffies(ACPI_EC_DELAY));
+       ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
+       ec->curr->done = false;
+       acpi_ec_write_cmd(ec, ec->curr->command);
 }
 
-static void ec_switch_to_poll_mode(struct acpi_ec *ec)
+static void advance_transaction(struct acpi_ec *ec, u8 status)
 {
-       set_bit(EC_FLAGS_NO_GPE, &ec->flags);
-       clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
-       acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
-       set_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
+       unsigned long flags;
+       spin_lock_irqsave(&ec->curr_lock, flags);
+       if (!ec->curr)
+               goto unlock;
+       if (ec->curr->wlen > ec->curr->wi) {
+               if ((status & ACPI_EC_FLAG_IBF) == 0)
+                       acpi_ec_write_data(ec,
+                               ec->curr->wdata[ec->curr->wi++]);
+               else
+                       goto err;
+       } else if (ec->curr->rlen > ec->curr->ri) {
+               if ((status & ACPI_EC_FLAG_OBF) == 1) {
+                       ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
+                       if (ec->curr->rlen == ec->curr->ri)
+                               ec->curr->done = true;
+               } else
+                       goto err;
+       } else if (ec->curr->wlen == ec->curr->wi &&
+                  (status & ACPI_EC_FLAG_IBF) == 0)
+               ec->curr->done = true;
+       goto unlock;
+err:
+       /* false interrupt, state didn't change */
+       if (in_interrupt())
+               ++ec->curr->irq_count;
+unlock:
+       spin_unlock_irqrestore(&ec->curr_lock, flags);
 }
 
-static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
+static int acpi_ec_sync_query(struct acpi_ec *ec);
+
+static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 {
-       atomic_set(&ec->irq_count, 0);
-       if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
-           likely(!force_poll)) {
-               if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
-                                      msecs_to_jiffies(ACPI_EC_DELAY)))
-                       return 0;
-               clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
-               if (acpi_ec_check_status(ec, event)) {
-                       /* missing GPEs, switch back to poll mode */
-                       if (printk_ratelimit())
-                               pr_info(PREFIX "missing confirmations, "
-                                               "switch off interrupt mode.\n");
-                       ec_switch_to_poll_mode(ec);
-                       ec_schedule_ec_poll(ec);
-                       return 0;
-               }
-       } else {
-               unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
-               clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
-               while (time_before(jiffies, delay)) {
-                       if (acpi_ec_check_status(ec, event))
-                               return 0;
-                       udelay(ACPI_EC_UDELAY);
-               }
+       if (state & ACPI_EC_FLAG_SCI) {
+               if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
+                       return acpi_ec_sync_query(ec);
        }
-       pr_err(PREFIX "acpi_ec_wait timeout, status = 0x%2.2x, event = %s\n",
-               acpi_ec_read_status(ec),
-               (event == ACPI_EC_EVENT_OBF_1) ? "\"b0=1\"" : "\"b1=0\"");
-       return -ETIME;
+       return 0;
 }
 
-static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
-                                       const u8 * wdata, unsigned wdata_len,
-                                       u8 * rdata, unsigned rdata_len,
-                                       int force_poll)
+static int ec_poll(struct acpi_ec *ec)
 {
-       int result = 0;
-       set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
-       pr_debug(PREFIX "transaction start\n");
-       acpi_ec_write_cmd(ec, command);
-       for (; wdata_len > 0; --wdata_len) {
-               result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
-               if (result) {
-                       pr_err(PREFIX
-                              "write_cmd timeout, command = %d\n", command);
-                       goto end;
-               }
-               set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
-               acpi_ec_write_data(ec, *(wdata++));
+       unsigned long flags;
+       int repeat = 2; /* number of command restarts */
+       while (repeat--) {
+               unsigned long delay = jiffies +
+                       msecs_to_jiffies(ec_delay);
+               do {
+                       /* don't sleep with disabled interrupts */
+                       if (EC_FLAGS_MSI || irqs_disabled()) {
+                               udelay(ACPI_EC_MSI_UDELAY);
+                               if (ec_transaction_done(ec))
+                                       return 0;
+                       } else {
+                               if (wait_event_timeout(ec->wait,
+                                               ec_transaction_done(ec),
+                                               msecs_to_jiffies(1)))
+                                       return 0;
+                       }
+                       advance_transaction(ec, acpi_ec_read_status(ec));
+               } while (time_before(jiffies, delay));
+               if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
+                       break;
+               pr_debug(PREFIX "controller reset, restart transaction\n");
+               spin_lock_irqsave(&ec->curr_lock, flags);
+               start_transaction(ec);
+               spin_unlock_irqrestore(&ec->curr_lock, flags);
        }
+       return -ETIME;
+}
 
-       if (!rdata_len) {
-               result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
-               if (result) {
-                       pr_err(PREFIX
-                              "finish-write timeout, command = %d\n", command);
-                       goto end;
-               }
-       } else if (command == ACPI_EC_COMMAND_QUERY)
+static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
+                                       struct transaction *t)
+{
+       unsigned long tmp;
+       int ret = 0;
+       if (EC_FLAGS_MSI)
+               udelay(ACPI_EC_MSI_UDELAY);
+       /* start transaction */
+       spin_lock_irqsave(&ec->curr_lock, tmp);
+       /* following two actions should be kept atomic */
+       ec->curr = t;
+       start_transaction(ec);
+       if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
                clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
+       spin_unlock_irqrestore(&ec->curr_lock, tmp);
+       ret = ec_poll(ec);
+       spin_lock_irqsave(&ec->curr_lock, tmp);
+       ec->curr = NULL;
+       spin_unlock_irqrestore(&ec->curr_lock, tmp);
+       return ret;
+}
 
-       for (; rdata_len > 0; --rdata_len) {
-               result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
-               if (result) {
-                       pr_err(PREFIX "read timeout, command = %d\n", command);
-                       goto end;
-               }
-               /* Don't expect GPE after last read */
-               if (rdata_len > 1)
-                       set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
-               *(rdata++) = acpi_ec_read_data(ec);
-       }
-      end:
-       pr_debug(PREFIX "transaction end\n");
-       return result;
+static int ec_check_ibf0(struct acpi_ec *ec)
+{
+       u8 status = acpi_ec_read_status(ec);
+       return (status & ACPI_EC_FLAG_IBF) == 0;
+}
+
+static int ec_wait_ibf0(struct acpi_ec *ec)
+{
+       unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
+       /* interrupt wait manually if GPE mode is not active */
+       while (time_before(jiffies, delay))
+               if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
+                                       msecs_to_jiffies(1)))
+                       return 0;
+       return -ETIME;
 }
 
-static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
-                              const u8 * wdata, unsigned wdata_len,
-                              u8 * rdata, unsigned rdata_len,
-                              int force_poll)
+static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 {
        int status;
        u32 glk;
-
-       if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
+       if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
                return -EINVAL;
-
-       if (rdata)
-               memset(rdata, 0, rdata_len);
-
+       if (t->rdata)
+               memset(t->rdata, 0, t->rlen);
        mutex_lock(&ec->lock);
+       if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
+               status = -EINVAL;
+               goto unlock;
+       }
        if (ec->global_lock) {
                status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
                if (ACPI_FAILURE(status)) {
-                       mutex_unlock(&ec->lock);
-                       return -ENODEV;
+                       status = -ENODEV;
+                       goto unlock;
                }
        }
-
-       status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
-       if (status) {
+       if (ec_wait_ibf0(ec)) {
                pr_err(PREFIX "input buffer is not empty, "
                                "aborting transaction\n");
+               status = -ETIME;
                goto end;
        }
+       pr_debug(PREFIX "transaction start\n");
+       /* disable GPE during transaction if storm is detected */
+       if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
+               /* It has to be disabled, so that it doesn't trigger. */
+               acpi_disable_gpe(NULL, ec->gpe);
+       }
 
-       status = acpi_ec_transaction_unlocked(ec, command,
-                                             wdata, wdata_len,
-                                             rdata, rdata_len,
-                                             force_poll);
-
-      end:
-
+       status = acpi_ec_transaction_unlocked(ec, t);
+
+       /* check if we received SCI during transaction */
+       ec_check_sci_sync(ec, acpi_ec_read_status(ec));
+       if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
+               msleep(1);
+               /* It is safe to enable the GPE outside of the transaction. */
+               acpi_enable_gpe(NULL, ec->gpe);
+       } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
+               pr_info(PREFIX "GPE storm detected, "
+                       "transactions will use polling mode\n");
+               set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
+       }
+       pr_debug(PREFIX "transaction end\n");
+end:
        if (ec->global_lock)
                acpi_release_global_lock(glk);
+unlock:
        mutex_unlock(&ec->lock);
-
        return status;
 }
 
-/*
- * Note: samsung nv5000 doesn't work with ec burst mode.
- * http://bugzilla.kernel.org/show_bug.cgi?id=4980
- */
-int acpi_ec_burst_enable(struct acpi_ec *ec)
+static int acpi_ec_burst_enable(struct acpi_ec *ec)
 {
        u8 d;
-       return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
+       struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
+                               .wdata = NULL, .rdata = &d,
+                               .wlen = 0, .rlen = 1};
+
+       return acpi_ec_transaction(ec, &t);
 }
 
-int acpi_ec_burst_disable(struct acpi_ec *ec)
+static int acpi_ec_burst_disable(struct acpi_ec *ec)
 {
-       return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
+       struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
+                               .wdata = NULL, .rdata = NULL,
+                               .wlen = 0, .rlen = 0};
+
+       return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
+                               acpi_ec_transaction(ec, &t) : 0;
 }
 
 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 {
        int result;
        u8 d;
+       struct transaction t = {.command = ACPI_EC_COMMAND_READ,
+                               .wdata = &address, .rdata = &d,
+                               .wlen = 1, .rlen = 1};
 
-       result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
-                                    &address, 1, &d, 1, 0);
+       result = acpi_ec_transaction(ec, &t);
        *data = d;
        return result;
 }
@@ -322,8 +369,11 @@ static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 {
        u8 wdata[2] = { address, data };
-       return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
-                                  wdata, 2, NULL, 0, 0);
+       struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
+                               .wdata = wdata, .rdata = NULL,
+                               .wlen = 2, .rlen = 0};
+
+       return acpi_ec_transaction(ec, &t);
 }
 
 /*
@@ -382,40 +432,74 @@ EXPORT_SYMBOL(ec_write);
 
 int ec_transaction(u8 command,
                   const u8 * wdata, unsigned wdata_len,
-                  u8 * rdata, unsigned rdata_len,
-                  int force_poll)
+                  u8 * rdata, unsigned rdata_len)
 {
+       struct transaction t = {.command = command,
+                               .wdata = wdata, .rdata = rdata,
+                               .wlen = wdata_len, .rlen = rdata_len};
        if (!first_ec)
                return -ENODEV;
 
-       return acpi_ec_transaction(first_ec, command, wdata,
-                                  wdata_len, rdata, rdata_len,
-                                  force_poll);
+       return acpi_ec_transaction(first_ec, &t);
 }
 
 EXPORT_SYMBOL(ec_transaction);
 
-static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
+void acpi_ec_block_transactions(void)
+{
+       struct acpi_ec *ec = first_ec;
+
+       if (!ec)
+               return;
+
+       mutex_lock(&ec->lock);
+       /* Prevent transactions from being carried out */
+       set_bit(EC_FLAGS_BLOCKED, &ec->flags);
+       mutex_unlock(&ec->lock);
+}
+
+void acpi_ec_unblock_transactions(void)
+{
+       struct acpi_ec *ec = first_ec;
+
+       if (!ec)
+               return;
+
+       mutex_lock(&ec->lock);
+       /* Allow transactions to be carried out again */
+       clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
+       mutex_unlock(&ec->lock);
+}
+
+void acpi_ec_unblock_transactions_early(void)
+{
+       /*
+        * Allow transactions to happen again (this function is called from
+        * atomic context during wakeup, so we don't need to acquire the mutex).
+        */
+       if (first_ec)
+               clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
+}
+
+static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 {
        int result;
        u8 d;
-
+       struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
+                               .wdata = NULL, .rdata = &d,
+                               .wlen = 0, .rlen = 1};
        if (!ec || !data)
                return -EINVAL;
-
        /*
         * Query the EC to find out which _Qxx method we need to evaluate.
         * Note that successful completion of the query causes the ACPI_EC_SCI
         * bit to be cleared (and thus clearing the interrupt source).
         */
-
-       result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
+       result = acpi_ec_transaction_unlocked(ec, &t);
        if (result)
                return result;
-
        if (!d)
                return -ENODATA;
-
        *data = d;
        return 0;
 }
@@ -459,73 +543,79 @@ void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 
 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 
-static void acpi_ec_gpe_query(void *ec_cxt)
+static void acpi_ec_run(void *cxt)
 {
-       struct acpi_ec *ec = ec_cxt;
-       u8 value = 0;
-       struct acpi_ec_query_handler *handler, copy;
-
-       if (!ec || acpi_ec_query(ec, &value))
+       struct acpi_ec_query_handler *handler = cxt;
+       if (!handler)
                return;
-       mutex_lock(&ec->lock);
+       pr_debug(PREFIX "start query execution\n");
+       if (handler->func)
+               handler->func(handler->data);
+       else if (handler->handle)
+               acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
+       pr_debug(PREFIX "stop query execution\n");
+       kfree(handler);
+}
+
+static int acpi_ec_sync_query(struct acpi_ec *ec)
+{
+       u8 value = 0;
+       int status;
+       struct acpi_ec_query_handler *handler, *copy;
+       if ((status = acpi_ec_query_unlocked(ec, &value)))
+               return status;
        list_for_each_entry(handler, &ec->list, node) {
                if (value == handler->query_bit) {
                        /* have custom handler for this bit */
-                       memcpy(&copy, handler, sizeof(copy));
-                       mutex_unlock(&ec->lock);
-                       if (copy.func) {
-                               copy.func(copy.data);
-                       } else if (copy.handle) {
-                               acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
-                       }
-                       return;
+                       copy = kmalloc(sizeof(*handler), GFP_KERNEL);
+                       if (!copy)
+                               return -ENOMEM;
+                       memcpy(copy, handler, sizeof(*copy));
+                       pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
+                       return acpi_os_execute((copy->func) ?
+                               OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
+                               acpi_ec_run, copy);
                }
        }
-       mutex_unlock(&ec->lock);
+       return 0;
 }
 
-static u32 acpi_ec_gpe_handler(void *data)
+static void acpi_ec_gpe_query(void *ec_cxt)
 {
-       acpi_status status = AE_OK;
-       struct acpi_ec *ec = data;
-       u8 state = acpi_ec_read_status(ec);
-
-       pr_debug(PREFIX "~~~> interrupt\n");
-       atomic_inc(&ec->irq_count);
-       if (atomic_read(&ec->irq_count) > 5) {
-               pr_err(PREFIX "GPE storm detected, disabling EC GPE\n");
-               ec_switch_to_poll_mode(ec);
-               goto end;
-       }
-       clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
-       if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
-               wake_up(&ec->wait);
+       struct acpi_ec *ec = ec_cxt;
+       if (!ec)
+               return;
+       mutex_lock(&ec->lock);
+       acpi_ec_sync_query(ec);
+       mutex_unlock(&ec->lock);
+}
 
+static int ec_check_sci(struct acpi_ec *ec, u8 state)
+{
        if (state & ACPI_EC_FLAG_SCI) {
-               if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
-                       status = acpi_os_execute(OSL_EC_BURST_HANDLER,
+               if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
+                       pr_debug(PREFIX "push gpe query to the queue\n");
+                       return acpi_os_execute(OSL_NOTIFY_HANDLER,
                                acpi_ec_gpe_query, ec);
-       } else if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
-                  !test_bit(EC_FLAGS_NO_GPE, &ec->flags) &&
-                  in_interrupt()) {
-               /* this is non-query, must be confirmation */
-               if (printk_ratelimit())
-                       pr_info(PREFIX "non-query interrupt received,"
-                               " switching to interrupt mode\n");
-               set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
-               clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
+               }
        }
-end:
-       ec_schedule_ec_poll(ec);
-       return ACPI_SUCCESS(status) ?
-           ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
+       return 0;
 }
 
-static void do_ec_poll(struct work_struct *work)
+static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
+       u32 gpe_number, void *data)
 {
-       struct acpi_ec *ec = container_of(work, struct acpi_ec, work.work);
-       atomic_set(&ec->irq_count, 0);
-       (void)acpi_ec_gpe_handler(ec);
+       struct acpi_ec *ec = data;
+
+       pr_debug(PREFIX "~~~> interrupt\n");
+
+       advance_transaction(ec, acpi_ec_read_status(ec));
+       if (ec_transaction_done(ec) &&
+           (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
+               wake_up(&ec->wait);
+               ec_check_sci(ec, acpi_ec_read_status(ec));
+       }
+       return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 }
 
 /* --------------------------------------------------------------------------
@@ -533,27 +623,13 @@ static void do_ec_poll(struct work_struct *work)
    -------------------------------------------------------------------------- */
 
 static acpi_status
-acpi_ec_space_setup(acpi_handle region_handle,
-                   u32 function, void *handler_context, void **return_context)
-{
-       /*
-        * The EC object is in the handler context and is needed
-        * when calling the acpi_ec_space_handler.
-        */
-       *return_context = (function != ACPI_REGION_DEACTIVATE) ?
-           handler_context : NULL;
-
-       return AE_OK;
-}
-
-static acpi_status
 acpi_ec_space_handler(u32 function, acpi_physical_address address,
-                     u32 bits, acpi_integer *value,
+                     u32 bits, u64 *value64,
                      void *handler_context, void *region_context)
 {
        struct acpi_ec *ec = handler_context;
-       int result = 0, i;
-       u8 temp = 0;
+       int result = 0, i, bytes = bits / 8;
+       u8 *value = (u8 *)value64;
 
        if ((address > 0xFF) || !value || !handler_context)
                return AE_BAD_PARAMETER;
@@ -561,31 +637,16 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
        if (function != ACPI_READ && function != ACPI_WRITE)
                return AE_BAD_PARAMETER;
 
-       if (bits != 8 && acpi_strict)
-               return AE_BAD_PARAMETER;
+       if (EC_FLAGS_MSI || bits > 8)
+               acpi_ec_burst_enable(ec);
 
-       acpi_ec_burst_enable(ec);
+       for (i = 0; i < bytes; ++i, ++address, ++value)
+               result = (function == ACPI_READ) ?
+                       acpi_ec_read(ec, address, value) :
+                       acpi_ec_write(ec, address, *value);
 
-       if (function == ACPI_READ) {
-               result = acpi_ec_read(ec, address, &temp);
-               *value = temp;
-       } else {
-               temp = 0xff & (*value);
-               result = acpi_ec_write(ec, address, temp);
-       }
-
-       for (i = 8; unlikely(bits - i > 0); i += 8) {
-               ++address;
-               if (function == ACPI_READ) {
-                       result = acpi_ec_read(ec, address, &temp);
-                       (*value) |= ((acpi_integer)temp) << i;
-               } else {
-                       temp = 0xff & ((*value) >> i);
-                       result = acpi_ec_write(ec, address, temp);
-               }
-       }
-
-       acpi_ec_burst_disable(ec);
+       if (EC_FLAGS_MSI || bits > 8)
+               acpi_ec_burst_disable(ec);
 
        switch (result) {
        case -EINVAL:
@@ -603,77 +664,6 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
 }
 
 /* --------------------------------------------------------------------------
-                              FS Interface (/proc)
-   -------------------------------------------------------------------------- */
-
-static struct proc_dir_entry *acpi_ec_dir;
-
-static int acpi_ec_read_info(struct seq_file *seq, void *offset)
-{
-       struct acpi_ec *ec = seq->private;
-
-       if (!ec)
-               goto end;
-
-       seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
-       seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
-                  (unsigned)ec->command_addr, (unsigned)ec->data_addr);
-       seq_printf(seq, "use global lock:\t%s\n",
-                  ec->global_lock ? "yes" : "no");
-      end:
-       return 0;
-}
-
-static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
-{
-       return single_open(file, acpi_ec_read_info, PDE(inode)->data);
-}
-
-static struct file_operations acpi_ec_info_ops = {
-       .open = acpi_ec_info_open_fs,
-       .read = seq_read,
-       .llseek = seq_lseek,
-       .release = single_release,
-       .owner = THIS_MODULE,
-};
-
-static int acpi_ec_add_fs(struct acpi_device *device)
-{
-       struct proc_dir_entry *entry = NULL;
-
-       if (!acpi_device_dir(device)) {
-               acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
-                                                    acpi_ec_dir);
-               if (!acpi_device_dir(device))
-                       return -ENODEV;
-       }
-
-       entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
-                                 acpi_device_dir(device));
-       if (!entry)
-               return -ENODEV;
-       else {
-               entry->proc_fops = &acpi_ec_info_ops;
-               entry->data = acpi_driver_data(device);
-               entry->owner = THIS_MODULE;
-       }
-
-       return 0;
-}
-
-static int acpi_ec_remove_fs(struct acpi_device *device)
-{
-
-       if (acpi_device_dir(device)) {
-               remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
-               remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
-               acpi_device_dir(device) = NULL;
-       }
-
-       return 0;
-}
-
-/* --------------------------------------------------------------------------
                                Driver Interface
    -------------------------------------------------------------------------- */
 static acpi_status
@@ -688,8 +678,7 @@ static struct acpi_ec *make_acpi_ec(void)
        mutex_init(&ec->lock);
        init_waitqueue_head(&ec->wait);
        INIT_LIST_HEAD(&ec->list);
-       INIT_DELAYED_WORK_DEFERRABLE(&ec->work, do_ec_poll);
-       atomic_set(&ec->irq_count, 0);
+       spin_lock_init(&ec->curr_lock);
        return ec;
 }
 
@@ -697,10 +686,15 @@ static acpi_status
 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
                               void *context, void **return_value)
 {
-       struct acpi_namespace_node *node = handle;
+       char node_name[5];
+       struct acpi_buffer buffer = { sizeof(node_name), node_name };
        struct acpi_ec *ec = context;
        int value = 0;
-       if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
+       acpi_status status;
+
+       status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
+
+       if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
                acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
        }
        return AE_OK;
@@ -710,8 +704,13 @@ static acpi_status
 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 {
        acpi_status status;
+       unsigned long long tmp = 0;
 
        struct acpi_ec *ec = context;
+
+       /* clear addr values, ec_parse_io_ports depend on it */
+       ec->command_addr = ec->data_addr = 0;
+
        status = acpi_walk_resources(handle, METHOD_NAME__CRS,
                                     ec_parse_io_ports, ec);
        if (ACPI_FAILURE(status))
@@ -719,80 +718,113 @@ ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 
        /* Get GPE bit assignment (EC events). */
        /* TODO: Add support for _GPE returning a package */
-       status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
+       status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
        if (ACPI_FAILURE(status))
                return status;
-       /* Find and register all query methods */
-       acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
-                           acpi_ec_register_query_methods, ec, NULL);
+       ec->gpe = tmp;
        /* Use the global lock for all EC transactions? */
-       acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
+       tmp = 0;
+       acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
+       ec->global_lock = tmp;
        ec->handle = handle;
        return AE_CTRL_TERMINATE;
 }
 
-static void ec_poll_stop(struct acpi_ec *ec)
+static int ec_install_handlers(struct acpi_ec *ec)
 {
-       clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
-       cancel_delayed_work(&ec->work);
+       acpi_status status;
+       if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
+               return 0;
+       status = acpi_install_gpe_handler(NULL, ec->gpe,
+                                 ACPI_GPE_EDGE_TRIGGERED,
+                                 &acpi_ec_gpe_handler, ec);
+       if (ACPI_FAILURE(status))
+               return -ENODEV;
+
+       acpi_enable_gpe(NULL, ec->gpe);
+       status = acpi_install_address_space_handler(ec->handle,
+                                                   ACPI_ADR_SPACE_EC,
+                                                   &acpi_ec_space_handler,
+                                                   NULL, ec);
+       if (ACPI_FAILURE(status)) {
+               if (status == AE_NOT_FOUND) {
+                       /*
+                        * Maybe OS fails in evaluating the _REG object.
+                        * The AE_NOT_FOUND error will be ignored and OS
+                        * continue to initialize EC.
+                        */
+                       printk(KERN_ERR "Fail in evaluating the _REG object"
+                               " of EC device. Broken bios is suspected.\n");
+               } else {
+                       acpi_remove_gpe_handler(NULL, ec->gpe,
+                               &acpi_ec_gpe_handler);
+                       acpi_disable_gpe(NULL, ec->gpe);
+                       return -ENODEV;
+               }
+       }
+
+       set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
+       return 0;
 }
 
 static void ec_remove_handlers(struct acpi_ec *ec)
 {
-       ec_poll_stop(ec);
+       acpi_disable_gpe(NULL, ec->gpe);
        if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
                                ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
                pr_err(PREFIX "failed to remove space handler\n");
        if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
                                &acpi_ec_gpe_handler)))
                pr_err(PREFIX "failed to remove gpe handler\n");
-       ec->handlers_installed = 0;
+       clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 }
 
 static int acpi_ec_add(struct acpi_device *device)
 {
        struct acpi_ec *ec = NULL;
+       int ret;
 
-       if (!device)
-               return -EINVAL;
        strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
        strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 
        /* Check for boot EC */
-       if (boot_ec) {
-               if (boot_ec->handle == device->handle) {
-                       /* Pre-loaded EC from DSDT, just move pointer */
-                       ec = boot_ec;
-                       boot_ec = NULL;
-                       goto end;
-               } else if (boot_ec->handle == ACPI_ROOT_OBJECT) {
-                       /* ECDT-based EC, time to shut it down */
-                       ec_remove_handlers(boot_ec);
-                       kfree(boot_ec);
-                       first_ec = boot_ec = NULL;
-               }
+       if (boot_ec &&
+           (boot_ec->handle == device->handle ||
+            boot_ec->handle == ACPI_ROOT_OBJECT)) {
+               ec = boot_ec;
+               boot_ec = NULL;
+       } else {
+               ec = make_acpi_ec();
+               if (!ec)
+                       return -ENOMEM;
        }
-
-       ec = make_acpi_ec();
-       if (!ec)
-               return -ENOMEM;
-
        if (ec_parse_device(device->handle, 0, ec, NULL) !=
-           AE_CTRL_TERMINATE) {
-               kfree(ec);
-               return -EINVAL;
+               AE_CTRL_TERMINATE) {
+                       kfree(ec);
+                       return -EINVAL;
        }
-       ec->handle = device->handle;
-      end:
+
+       /* Find and register all query methods */
+       acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
+                           acpi_ec_register_query_methods, NULL, ec, NULL);
+
        if (!first_ec)
                first_ec = ec;
-       acpi_driver_data(device) = ec;
-       acpi_ec_add_fs(device);
+       device->driver_data = ec;
+
+       WARN(!request_region(ec->data_addr, 1, "EC data"),
+            "Could not request EC data io port 0x%lx", ec->data_addr);
+       WARN(!request_region(ec->command_addr, 1, "EC cmd"),
+            "Could not request EC cmd io port 0x%lx", ec->command_addr);
+
        pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
                          ec->gpe, ec->command_addr, ec->data_addr);
-       pr_info(PREFIX "driver started in %s mode\n",
-               (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
-       return 0;
+
+       ret = ec_install_handlers(ec);
+
+       /* EC is fully operational, allow queries */
+       clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
+       return ret;
 }
 
 static int acpi_ec_remove(struct acpi_device *device, int type)
@@ -804,14 +836,16 @@ static int acpi_ec_remove(struct acpi_device *device, int type)
                return -EINVAL;
 
        ec = acpi_driver_data(device);
+       ec_remove_handlers(ec);
        mutex_lock(&ec->lock);
        list_for_each_entry_safe(handler, tmp, &ec->list, node) {
                list_del(&handler->node);
                kfree(handler);
        }
        mutex_unlock(&ec->lock);
-       acpi_ec_remove_fs(device);
-       acpi_driver_data(device) = NULL;
+       release_region(ec->data_addr, 1);
+       release_region(ec->command_addr, 1);
+       device->driver_data = NULL;
        if (ec == first_ec)
                first_ec = NULL;
        kfree(ec);
@@ -841,87 +875,84 @@ ec_parse_io_ports(struct acpi_resource *resource, void *context)
        return AE_OK;
 }
 
-static int ec_install_handlers(struct acpi_ec *ec)
+int __init acpi_boot_ec_enable(void)
 {
-       acpi_status status;
-       if (ec->handlers_installed)
+       if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
+               return 0;
+       if (!ec_install_handlers(boot_ec)) {
+               first_ec = boot_ec;
                return 0;
-       status = acpi_install_gpe_handler(NULL, ec->gpe,
-                                         ACPI_GPE_EDGE_TRIGGERED,
-                                         &acpi_ec_gpe_handler, ec);
-       if (ACPI_FAILURE(status))
-               return -ENODEV;
-
-       acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
-       acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
-
-       status = acpi_install_address_space_handler(ec->handle,
-                                                   ACPI_ADR_SPACE_EC,
-                                                   &acpi_ec_space_handler,
-                                                   &acpi_ec_space_setup, ec);
-       if (ACPI_FAILURE(status)) {
-               acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
-               return -ENODEV;
        }
-
-       ec->handlers_installed = 1;
-       return 0;
+       return -EFAULT;
 }
 
-static int acpi_ec_start(struct acpi_device *device)
-{
-       struct acpi_ec *ec;
-       int ret = 0;
-
-       if (!device)
-               return -EINVAL;
-
-       ec = acpi_driver_data(device);
-
-       if (!ec)
-               return -EINVAL;
-
-       ret = ec_install_handlers(ec);
+static const struct acpi_device_id ec_device_ids[] = {
+       {"PNP0C09", 0},
+       {"", 0},
+};
 
-       /* EC is fully operational, allow queries */
-       clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
-       ec_schedule_ec_poll(ec);
-       return ret;
+/* Some BIOS do not survive early DSDT scan, skip it */
+static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
+{
+       EC_FLAGS_SKIP_DSDT_SCAN = 1;
+       return 0;
 }
 
-static int acpi_ec_stop(struct acpi_device *device, int type)
+/* ASUStek often supplies us with broken ECDT, validate it */
+static int ec_validate_ecdt(const struct dmi_system_id *id)
 {
-       struct acpi_ec *ec;
-       if (!device)
-               return -EINVAL;
-       ec = acpi_driver_data(device);
-       if (!ec)
-               return -EINVAL;
-       ec_remove_handlers(ec);
-
+       EC_FLAGS_VALIDATE_ECDT = 1;
        return 0;
 }
 
-int __init acpi_boot_ec_enable(void)
+/* MSI EC needs special treatment, enable it */
+static int ec_flag_msi(const struct dmi_system_id *id)
 {
-       if (!boot_ec || boot_ec->handlers_installed)
-               return 0;
-       if (!ec_install_handlers(boot_ec)) {
-               first_ec = boot_ec;
-               return 0;
-       }
-       return -EFAULT;
+       printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
+       EC_FLAGS_MSI = 1;
+       EC_FLAGS_VALIDATE_ECDT = 1;
+       return 0;
 }
 
-static const struct acpi_device_id ec_device_ids[] = {
-       {"PNP0C09", 0},
-       {"", 0},
+static struct dmi_system_id __initdata ec_dmi_table[] = {
+       {
+       ec_skip_dsdt_scan, "Compal JFL92", {
+       DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
+       DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
+       {
+       ec_flag_msi, "MSI hardware", {
+       DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
+       {
+       ec_flag_msi, "MSI hardware", {
+       DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
+       {
+       ec_flag_msi, "MSI hardware", {
+       DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
+       {
+       ec_flag_msi, "MSI hardware", {
+       DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
+       {
+       ec_flag_msi, "Quanta hardware", {
+       DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
+       DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
+       {
+       ec_flag_msi, "Quanta hardware", {
+       DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
+       DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
+       {
+       ec_validate_ecdt, "ASUS hardware", {
+       DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
+       {
+       ec_validate_ecdt, "ASUS hardware", {
+       DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
+       {},
 };
 
+
 int __init acpi_ec_ecdt_probe(void)
 {
-       int ret;
        acpi_status status;
+       struct acpi_ec *saved_ec = NULL;
        struct acpi_table_ecdt *ecdt_ptr;
 
        boot_ec = make_acpi_ec();
@@ -930,6 +961,7 @@ int __init acpi_ec_ecdt_probe(void)
        /*
         * Generate a boot ec context
         */
+       dmi_check_system(ec_dmi_table);
        status = acpi_get_table(ACPI_SIG_ECDT, 1,
                                (struct acpi_table_header **)&ecdt_ptr);
        if (ACPI_SUCCESS(status)) {
@@ -938,54 +970,61 @@ int __init acpi_ec_ecdt_probe(void)
                boot_ec->data_addr = ecdt_ptr->data.address;
                boot_ec->gpe = ecdt_ptr->gpe;
                boot_ec->handle = ACPI_ROOT_OBJECT;
+               acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
+               /* Don't trust ECDT, which comes from ASUSTek */
+               if (!EC_FLAGS_VALIDATE_ECDT)
+                       goto install;
+               saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
+               if (!saved_ec)
+                       return -ENOMEM;
+       /* fall through */
+       }
+
+       if (EC_FLAGS_SKIP_DSDT_SCAN)
+               return -ENODEV;
+
+       /* This workaround is needed only on some broken machines,
+        * which require early EC, but fail to provide ECDT */
+       printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
+       status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
+                                       boot_ec, NULL);
+       /* Check that acpi_get_devices actually find something */
+       if (ACPI_FAILURE(status) || !boot_ec->handle)
+               goto error;
+       if (saved_ec) {
+               /* try to find good ECDT from ASUSTek */
+               if (saved_ec->command_addr != boot_ec->command_addr ||
+                   saved_ec->data_addr != boot_ec->data_addr ||
+                   saved_ec->gpe != boot_ec->gpe ||
+                   saved_ec->handle != boot_ec->handle)
+                       pr_info(PREFIX "ASUSTek keeps feeding us with broken "
+                       "ECDT tables, which are very hard to workaround. "
+                       "Trying to use DSDT EC info instead. Please send "
+                       "output of acpidump to linux-acpi@vger.kernel.org\n");
+               kfree(saved_ec);
+               saved_ec = NULL;
        } else {
-               /* This workaround is needed only on some broken machines,
-                * which require early EC, but fail to provide ECDT */
-               acpi_handle x;
-               printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
-               status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
-                                               boot_ec, NULL);
-               /* Check that acpi_get_devices actually find something */
-               if (ACPI_FAILURE(status) || !boot_ec->handle)
-                       goto error;
                /* We really need to limit this workaround, the only ASUS,
-                * which needs it, has fake EC._INI method, so use it as flag.
-                * Keep boot_ec struct as it will be needed soon.
-                */
-               if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
+               * which needs it, has fake EC._INI method, so use it as flag.
+               * Keep boot_ec struct as it will be needed soon.
+               */
+               acpi_handle dummy;
+               if (!dmi_name_in_vendors("ASUS") ||
+                   ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
+                                                       &dummy)))
                        return -ENODEV;
        }
-
-       ret = ec_install_handlers(boot_ec);
-       if (!ret) {
+install:
+       if (!ec_install_handlers(boot_ec)) {
                first_ec = boot_ec;
                return 0;
        }
-      error:
+error:
        kfree(boot_ec);
        boot_ec = NULL;
        return -ENODEV;
 }
 
-static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
-{
-       struct acpi_ec *ec = acpi_driver_data(device);
-       /* Stop using GPE */
-       set_bit(EC_FLAGS_NO_GPE, &ec->flags);
-       clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
-       acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
-       return 0;
-}
-
-static int acpi_ec_resume(struct acpi_device *device)
-{
-       struct acpi_ec *ec = acpi_driver_data(device);
-       /* Enable use of GPE back */
-       clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
-       acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
-       return 0;
-}
-
 static struct acpi_driver acpi_ec_driver = {
        .name = "ec",
        .class = ACPI_EC_CLASS,
@@ -993,45 +1032,27 @@ static struct acpi_driver acpi_ec_driver = {
        .ops = {
                .add = acpi_ec_add,
                .remove = acpi_ec_remove,
-               .start = acpi_ec_start,
-               .stop = acpi_ec_stop,
-               .suspend = acpi_ec_suspend,
-               .resume = acpi_ec_resume,
                },
 };
 
-static int __init acpi_ec_init(void)
+int __init acpi_ec_init(void)
 {
        int result = 0;
 
-       if (acpi_disabled)
-               return 0;
-
-       acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
-       if (!acpi_ec_dir)
-               return -ENODEV;
-
        /* Now register the driver for the EC */
        result = acpi_bus_register_driver(&acpi_ec_driver);
-       if (result < 0) {
-               remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
+       if (result < 0)
                return -ENODEV;
-       }
 
        return result;
 }
 
-subsys_initcall(acpi_ec_init);
-
 /* EC driver currently not unloadable */
 #if 0
 static void __exit acpi_ec_exit(void)
 {
 
        acpi_bus_unregister_driver(&acpi_ec_driver);
-
-       remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
-
        return;
 }
 #endif /* 0 */